Catheterization and interventional procedures, such as angioplasty or stenting, generally are performed by inserting a hollow needle through a patient's skin and tissue into the vascular system. A guide wire may be advanced through the needle and into the patient's blood vessel accessed by the needle. The needle is then removed, enabling an introducer sheath to be advanced over the guide wire into the vessel, e.g., in conjunction with or subsequent to a dilator.
A catheter or other device may then be advanced through a lumen of the introducer sheath and over the guide wire into a position for performing a medical procedure. Thus, the introducer sheath may facilitate introducing various devices into the vessel, while minimizing trauma to the vessel wall and/or minimizing blood loss during a procedure.
In practice, the introducer sheath is generally inserted into the patient's vasculature using the modified Seldinger technique. In the Seldinger technique, a needle is first inserted into the vessel and a guidewire then follows through the needle. Next, the needle is removed and a sheath/dilator combination is advanced over the guidewire. The dilator expands the puncture in the vessel to a size suitable to receive the distal end of an introducer sheath. After the distal end of the sheath is disposed within the vessel, the dilator and guidewire are removed, thereby allowing access to the vessel lumen or other body lumen via the inserted introducer sheath.
Upon completing the procedure, the devices and introducer sheath would be removed, leaving a puncture site, i.e. an arteriotomy in the vessel wall. Traditionally, external pressure would be applied to the puncture site until clotting and wound sealing occur; however, the patient must remain bedridden for a substantial period after clotting to ensure closure of the wound. This procedure, however, may be time consuming and expensive, requiring as much as an hour of a physician's or nurse's time. It is also uncomfortable for the patient and requires that the patient remain immobilized in the operating room, catheter lab, or holding area. In addition, a risk of hematoma exists from bleeding before hemostasis occurs. Risks of additional complications can also include pseudo aneurism, retro-peritoneal hematoma, and/or A-V fistula.
Various apparatus have been suggested for percutaneously sealing a vascular puncture by occluding the puncture site. For example, U.S. Pat. Nos. 5,192,302 and 5,222,974, issued to Kensey et al., describe the use of a biodegradable plug that may be delivered through an introducer sheath into a puncture site. Another technique has been suggested that involves percutaneously suturing the puncture site, such as that disclosed in U.S. Pat. No. 5,304,204, issued to Hathaway et al. Such apparatuses were designed for permanent deployment, without regard for subsequent removal.